The horseshoe crab is a living fossil, but it supplies factors that are still crucial to endotoxin tests. Crab protection, then, is a biomedical priority, at least until animal-free alternatives ...

To test for endotoxin levels, Charles River produce instrumentation and test kits, with one of the devices called the PTS, a point-of-use spectrophotometer.

"With this general method, we are already detecting endotoxins at levels that are relevant for water quality testing, but the test can also be further optimized to detect even lower concentrations." ...